Enhancement of HTC in Heat Exchangers Using Nanofluids

Fluid heating and cooling play an important role in many industries including thermal power stations, production processes, petrochemical and electronic components. The heat transfer enhancement methods in different processes are abundant. Most of these methods are based on structure variation, extended surfaces (fins), vibration of heated surface and inserts (twisted tape, longitudinal strip and helical coil inserts). These techniques of enhancement hardly meet the ever increasing requirement for heat transfer and the compactness of the devices in processes involving electronic chips, laser applications or high-energy devices. In this regard improvement of the thermal properties of energy transmission fluids has become one of the methods of augmenting heat transfer. Traditional heat transfer fluids such as water, ethylene glycol and engine oil have inherently low thermal conductivity relative to metals and even metal oxides. Recent interest in the use of ultra-fine metallic or nonmetallic particles of nanometer (10-9 meters) dimension has renewed interest in using suspended particles as heat transfer fluids. .